When Dumbbell Bench Pressing - focus on tucking your elbows to keep your pec tendon and shoulder joint safe from injury. A cue I like to think of is making the shape of a triangle with my hands while bench pressing or a shape of an upside-down V with my hands. This will result in a slight rotation of your hands.

0:00-0:13 - intro
0:13-0:31 - dumbbell bench example
0:31 - 1:00 - elbow tracking
1:01-1:33 - example dumbbell bench